Preparation of typing antisera specific for O antigens of Pseudomonas aeruginosa

Abstract

Results of serotyping [to study cross infections in nosocomial disease] 966 clinical isolates of P. aeruginosa showed that 72% agglutinated specifically in one or another of the 16 typing antisera, but 28% agglutinated in .gtoreq. 2 and often in as many as 10 antisera; this polyagglutinability correlated with a high incidence of cross-reactivity among the antisera. Absorption of each typing [rabbit] antiserum with cell suspensions of 5 O-type strains or with a suspension of a particular polyagglutinable strain (SMC 247) abolished cross-reactivity in the typing antisera without significantly reducing titers against the homologous strains. All but 4 polyagglutinable strains agglutinated specifically in one or another absorbed antisera. The cross-reactions of unabsorbed antisera were interpreted as caused by antibodies directed not against specific O antigens but against thermostable specificities that remain undefined.